Sulphonic acid compounds and their preparation



Patented Dec. 16, 1941 COMPOUNDS AND THEIR ARATION SULPHONIO Ali?!) 2,266,084 OFFICE Alexander N. Sachanen, Arlie A. OKelly, and Phares G. Waldo, Woodbury, N. 1., assignors to Socony-Vacuum Oil Company, Incorporated, New York, N. Ye, a corporation of New York No Drawing. Application Serial No. 336.71

17 Claims.

This application is directed to the preparation of mineral oil sulphonic acid compounds and related products, and particularly relates to the preparation of petroleum sulphonic acid com-- pounds. This application is a continuation-inpart of our copending application 8. N. 125,266, filed February 11, 1937.

When petroleum fractions are treated with sulphuric acid, particularly with strong acid or oleum, certain acidic materials partaking of the nature of the known sulphonic acid compounds are formed. These mineral oil sulphonic acids and their salts or sulphonates, which frequently are designated in the industry as soaps," have long been important articles of commerce without, however, any specific or detailed knowledge of their exact. character, manner of formation, differences between members of the group,variation of properties between members of the group, and the like, having been gained.

Prior practice in the preparation of these bodies and knowledge of their properties, may be 1 shortly summarized as follows: Mineral oil is treated with strong sulphuric acid or oleum, either for refinement oi the oil or specifically for production of sulphonic bodies, either in one stage or many stages, the resulting sludge being separated from the oil. The oil is then treated with an aqueous solution of an alcohol or acetone, before or after neutralization with alkali, and the sulphonic acids or sulphonic acid soaps recovered from the aqueous extract. The sulphonic acids thus recovered are commonly designated mahogany or brown acids, because of color, and are usually characterized by a solubility in oil which is much greater than their solubility in water. The sludge separated from the above operation, after dilution with water to remove most of the remaining sulphuric acid, may be extracted-with oil for recovery of a further quantity of brown acids, which are then separated from the oil as outlined above. The remaining sludge upon disection with ,water, with or without neutraliza.-. tion, yields sulphonic acids of another kind, whose compounds may be salted out of thegresultina aqueous extract. Because of their color, these acids are known as green acids and generally. exhibitthe property of low solubility inch, with better solubility in water. Various refinements of process, tending to give sulphonic acids and,

soaps more free from oil have been proposed, and attempts to modify relative solubility by mixing brown and green acids have been made, but .no general knowledge has been attained leading to the ability to exercise control over the nature, preparation, and specific properties of sulphonic acids and compounds thereof. This invention is specifically directed to methods enabling controlled production of sulphonic acid products of predetermined characteristics.

Dial? 23, 1940,

' mined solubility properties.

It is an object of this invention to provide a method enabling the production of brown mineral oil sulphonic acid products of controlled solubility ticularly for some one of the uses to which sulphonated products are put. the provision of a method for producing brown mineral oil sulphonic acid products of predeter- Still another object is the provision of certainnovel brown mineral oil sulphonic acid products. One specific object is the production of abrown petroleum sulphonate which is highly water soluble and oil insoluble. Other objects are in part obvious and will in part appear from the following description of the invention.

This invention is based upon the discovery that with starting materials of controlled chemical nature and physical characteristics, sulphonated with controlled amounts of sulphonating agent of varying controlled strength, in a plurality of stages, followed by separation and isolation of the that it permits the production of sulphonicacid compounds manufactured to fit desired uses,

rather than compelling the adaption of the desired use to the fortuitously occurring properties of the sulphonic acid compound,

The mineral oil to be used should contain a substantial amount of cyclic hydrocarbons, i. e., aromatics and/or naphthenes, as distinguished from non-cyclic or paraflijnic compounds. Several petroleum oil products, as is well known, meet the above requirement, and we particularly prefer these petroleum oils.

One of the preferred starting materials of controlled nature are fractions obtained by distillation from solvent tars originating from the refining of lubricatingiractions of petroleum. Solvent character. Such solvents alone may be used upon he distillates of parafiinic or mixed base stocks originating from Pennsylvania or Mid-Continent types of crudes. Incompany with a preferential solvent for paraiilnic bodies, such as for example Another object is Rumble...

' sidual lubricant fractions from those stocks or distillates from other stocks. In the above discussion the terms paraflinic and naphthenic are not used in the strict chemical sense, but in that adopted by the oil industry, paraillnic designating those classes of compounds exhibiting low rate of decrease of viscosity with increase of temperature, and naphthenic designating compounds with high rate. Solvent extracts as produced by the processes noted above are designated solvent tars. Solvent tars of the kinds produced from oils of parafllnic or mixed base origin are particularly useful for the purposes of this invention. The solvent tar selected is preferably subjected to distillation under vacuum and those fractions by oils of similarboiling-polnt from solvent tars produced by any of the usual solvents. Similar fractions may be isolated by somewhat similar methodsfrom some tars produced by cracking.

Other preferred petroleum oils for our invention comprise low viscosity neutral distillates containing substantial amounts of cyclic hydrocarbons, such as the distillates employed in the manufacture of transformer oils. These transformer oil stocks are particularly preferred for the manufacture of water soluble, oil insoluble brown sulphonates and such sulphonates are excellent wetting and penetrating agents, and, for the manufacture of such agents, the transformer oil stock that is to be sulphonated should have a pour point below F. before dewaxing. Thus distillate oils containing a substantial amount of cyclic hydrocarbons, as for example, Coastal distillates, i. e., distillates from naphthenic crudes, having a viscosity between about 50 seconds and 100 seconds Saybolt Universal viscosity at 100 F. and having a pour point below zero degrees F. before dewaxing, may be sulphonated to produce a brown-sulphonate product which is extremely water soluble and oil insoluble and when substantially freed of oil is an excellent wettin or penetrating agent.

We prefer sulfuric acid as the sulphonating agent although, as known, other agents may be used for sulphonating. The strength'of the acid to be used depends upon the solubility desired in the resultant sulphonic acid product. Thus, we have foimd that when, for instance, the abovementioned solvent tar distillate fraction containing a substantial amount of cyclic hydrocarbons is subjected to successive treatments with sulphuric acid according to the following schedule, sulphonic acid products of different solubility properties are produced by the different treats.

Amount Strength Treat number r f acid. volume H3801 Percent Percent Each treatment is conducted byagitation with 7 the acid, followed by settling, separation, and withdrawal of the sludge formed. After removal of sludge is complete, the oil is treated with an aqueous extraction agent consisting of about 5 equal parts of ethyl alcohol and water. Other 10 such as neutralization and salting out, etc.. which maybe applicable to the particular circumstances.

The sulphonic acid products so formed exhibit a gradation of properties from .one end of the series to the other. Thus, for instance, the usual sulphonates, such as for example those of the alkaline group, of the sulphonic acids produced by sulphon'ation steps 3 and higher are increasingly oil-soluble, decreasingly water-soluble, sub:

stantially insoluble in water from step 6 on, in-

clusive. Those produced by steps 5 to 1 inclusive, (note reverse rder) are increasingly water-soluble and decreasingly oil-soluble, and below 3 are substantially insoluble in oil. Those produced by steps 1 and 2, water-soluble, oil-insoluble, resemble in some respects the green" acid sulphonates heretofore produced. Those produced by some of the higher steps resemble in some respects the mahogany or brown acid sulphonates heretofore produced. Both, however,

difler from such former sulphonates in many respects.

By separately recovering the brown acid products resulting from treats of different intensities,

we obtain products having only constituents of ,essentially the same solubility properties. In the above examples, sulphonates derived from the middle treats, e. g., treating steps 3, 4 and 5 contain essentially only components which are both water and oil soluble and, therefore, this product is particularly valuable, for uses which employ this type sulphonate. These sulphonic acids of-treats 3, 4 and 5 and their soaps, being quite soluble in both oil and water, a mixture of these products, or any one of them, is found quite useful in the preparation of permanently stable emulsions of hydrocarbon oils with water of any usual degree of hardness or salinity. Obviously if a water and oil soluble product is 0 desired, treats 3, 4 and 5 may be recovered together or separately, and, further, if "shading oil!" in solubility in either direction is desired, be recovered with or mixed with sulphonates of appropriately different properties. The sulphonate product derived from treat 6 is essentially oil soluble and water insoluble consisting almost exclusively of such constituents.

Conversely, the sulphonates, as for example,

the alkali 'metal sulphonates. of the sulphonic acids from the first two treats are highly water soluble and oil insoluble, and in this respect, might be said to resemble green sulphonates. However the sulphonates from treats 1 and 3 have a light brown or yellow color while green acids are, as the name indicates, green or even greenish black. Further green, sulphonic acids are insoluble in the oil, as evidenced by their source, as also are the green sulphonates: while, 0 on the other hand, the brown sulphonic acids of treats 1 and 2 are soluble in the oil while their sulphonates are insoluble in the oil. These water soluble, oil insoluble brown sulphonates when substantially freed from oil, which may be done in known manner, have proven to be exs eam exhibiting to an unusual degree the valuable ceptionally fine wetting and penetrating agents,

tioned transformer oil stocks. Accordingly, if it should-be desired to produce only this one product, it is obvious from the above, that the oil, such aswe propose to use, only need be treated with acid of similar concentration to that of treats l or 2, in one or preferably a plurality of treats with or; without separation between each treat, without continuing om through the rest of the series of treats at gher concentrastarts producing sulphonic acids whose sul-' phonates are both water and oil soluble rather than water soluble and oil insoluble, from the solvent tar distillate abovementioned, is somewhere between 98% acid and 103%. acid. Accordingly it is clear that if only the water soluble, oil insoluble sulphonate is desired the acid in the treats must be maintained below the concentration at which oil soluble sulphonates are formed.

The acids produced by the several steps likewise exhibit a gradationsof molecular weight increasing with the stage of treatment, In treating a 200-300 C. (under 1 in.Hg) distillate from solvent tar, for instance, the acids from stages 3, 4, and v5, have molecular-weights of the order of350, and, of course, those of stages 1. and 2 have smaller molecular weights while those of stage 6 are larger. Since, therefore, molecular weight of the hydrocarbons also regulates the properties of the sulphonates, if best results are to be obtained in treating petroleum distillates containing a substantial amountof cyclic hydrocarbons according to, our invention,

partieularly when produced'from the abovemen- L properties of mutual solubility in waterand oil,

- the following may be noted.

-tions shown in the example. It will be noticed from the example that the point where the acid Solvent tar produced by treatment oi a lubricating oildistillatefrom Pennsylvania Crude with dichlorodiethyl ether was subjected to vacuum distillation under an absolute pressure of mm pound per square inch of mercury, and those portions of the distillate coming over between 200 c. and 300 C. were collected together. This distillate was then treated with five successive treats of sulphuric acid using one part acid to ten parts oil, by volume, in each treatment, the first being conducted with acid containing 94% 11:80, the second with 98% acid, and the last three with 103% acid. In each step,-after agitating the acid and oil, the sludge was allowed 3 to settle, separated, and discarded, and the oil was treated with about 10% by volume of an extractive'solvent consisting of about equal parts of ethyl alcohol and water. The extracts from 5% of oil. It was indicated, by examination,

that the sulphonic acids present were possessed,

of a molecular weight of about 350. This sodium soap was found to be readily soluble in both oil and water, and particularly. suitablefor the preparation of so-called soluble oils, or mineral oil ii-actions emulsiflable in Since the calcium soaps of these acids are water-soluble to a high degree, the oils so made are permadistillates which are of more or less similar boil-i ing range or viscosity to the solvent tar distillates or transformer 011 stocks herein described should :be used so that the compounds therein are of somewhat similar molecular weight, it being understood that heavier stocks may be used but will tend to give poorer yields of the water soluble, oil insoluble sulphonates and iighter'stocks will tend to give poorer yields of the water insoluble, oil soluble sulphonates, v since, if all the compounds in the oil being treated are, for instance, substantially heavier than the lighter cyclic compounds in the above preferred distillates, the "early stage sulphonates will be less watersolublep I It is believed-thatthe progressively graded differences inproperties of the sulphonic acid compoundspr'oduced in' way depend upon the type of structure of'the hydrocarbon oil in- *voived. It'is believed that those produced by the firststage operations are relatively more aromatic or cyclic than aliphatic-in 'naturejand "that as the sulphonation--proceeds through sucnently emulsifiable even in. water of unusual hardness, very stable emulsions being formed even in water containing as much as 1 or 2 grams of calcium chloride (anhydride) per liter of wa- In order to further illustrate the invention with particular; respect to the formation of water soluble, oil insoluble brown sulphonates, the following data is given:

' Saybolt s ulphuric acid Propertyofsodium 'iypooil m used in treat sulphonateofsulat E per bbl, ofoll. phonic acids.

- Seconds Coastaldistil- 54 to 69 43 lbs. of 93% acid Highly water sollat (added in a pluable and oil inrallty of treats). soluble. Do 54in 59.--- 70 lbs. 0! 98%-a d .100, w (added in a pluraiity of treats). Do...-... 72 to 79.: 50 lbs. 01989,, sold Do, v I (added in a pluv rality of treats).

The water soluble, oil insoluble brown Sui-r phonates and the sulphonic acids fromlwhich "that th'ey are best recovered from the acid treated oil stock by means of an "acid jelly. Thus,

non-cyclic or parafiinic compounds and from Q asphaltic compounds. It is believed that the unique properties 'of mostof the-members of the series can be traced to their starting material, and are made evident by the method of. preparation used.

A As anexa'mple oia sulphonic acidpreparation after-the oil is sulp lionated and settled to separate sludge, the remaining sour oil is treated .with a small amount of water, e. g.', 1%, where- K by an acid jelly" is formed in the oil. "This -acid jelly" which contains the brown sulphonic acid products in question. is settled and separated from the oil. After separation the acid jelly" is neutralized and than permitted to settle three layers, via, a top all layer, a middle em sion layer and a lower aqueous layer contain-' ing the brown sulphonates. The lower aqueous layer is carefully withdrawn, treated with naphtha to extract submantially all remaining oil, and then the brown sulphonates are salted out yielding a product which consists oi brown sulphonates and water with a negligible amount of oil and a minor amount of salt. The slimy salted out product is preferably dried directly for a finished product in the form of either flakes or powder. however, the slimy material may be redissolved in water for a finished product in the form of an aqueous solution.

It is to be understood that the examples and specific data herein set forth are disclosed for the purposes of illustration only, and that the invention is not understood to be limited thereby or thereto, but is only subject to suchlimitations as may be expressed in the appended claims.

We claim:

1. A process for the production of mineral oil sulphonic acids comprising the following steps: Sulphonating a mineral oil fraction boiling in the range of from about 100 C. to about 300 C. at about 1 inch mercury absolute pressure which is relatively free of paraiilnic constituents and asphaltic constituents with successive treatments of sulphuric acid, using acid of only sufficient strength to produce water-soluble brown sulphonic acid products at first then increasing the strength of the acid treats to produce waterinsoluble bmwn sulphonic acid products, and separately recovering from the oil brown sulphonic acid products produced by treats. of different intensities, whereby a series of sulphonic acid products are obtained which difi'er from one another in properties.

2. A process for the production of mineral oil sulphonic acid products of varying solubilities in oil and water comprising the following steps: Treating a lubricant fraction with an extractive solvent to separate therefrom a solvent tar consisting predominantly of the naphthenic constituents present in said oil, subjecting the solvent tar to non-cracking distillation, collecting. the distillate portions thereof boiling at temperatures in the range of 200-300 C. at 1 inch mercury absolute pressure, subjecting the collected distillate to successive treatments with controlled amounts of sulphuric acid of controlled strength, at least some of said treatments being of different intensity, separating and removing sludge and free acid after each treatment, and after each treatment separately recovering the sulphonic acids remaining in the oil at that stage, the series of sulphonic acid products so recovered diifering one from another in properties.

3. A process for the production of mineral oil sulphonic acid products of varying solubilities in oil and water comprising the following steps:

' Treating a lubricant fraction of a paramnic base or mixed base crude with an extractive solvent to separate therefrom a solvent tar consisting predominantly of the naphthenic constituents present in said oil, subjecting the solvent tar to non-cracking distillation, collectin the distillate portions thereof boiling at temperatures in the range of 200-300 C. at 1 inch mercury absolute pressure, subjecting the collected distillate to successive treatments with controlled amounts of sulphuric acid of conbeing of different intensity, separating and removing sludge and free acid after each treatment, and. after each treatment separately recovering the sulphonic acids remaining in the oil at that stage, the series of sulphonic acid products so recovered differing one from another in properties.

4. A process for the production of mineral oil sulphonic acid bodies highly soluble in both oil and water comprising the following steps: Treating a lubricant fraction of a parafllnic base or mixed base crude with an extractive solvent to separate therefrom a solvent tar consisting predominantly of the naphthenic constituents present in said oil, subjecting the solvent tar to noncracking distillation, collecting the distillate portions thereof boizing at temperatures in the range of loll-300C. at 1 inch mercury absolute pressure, subjecting the collected distillate to successive treatments with controlled amounts of sulphuric acid of controlled strength, at least some of said treatments being of different intensity, separating and removing sludge and free acid after each treatment, and after each treatment separately recovering the sulphonic acids remaining in the oil at that stage, the series of sulphonic acid products so recovered exhibiting high water solubility and low oil solubility in the first stages, progressively changing to low water solubility and high oil solubility in the latest stages, and collecting the one or more intermediate stage products exhibiting relatively high solubility in both oil and water.

5. The process of claim 1 in which the acid treatment is by successive volumes of acid each amounting tmabout 10%-iby. volume of..the oil treated and in which the strength of the acid, expressed as per cent H2304 is about 94% in the first treatment, 98% in the second treatment, and 103% in succeeding treatments.

6. The process of claim 2 in which the said acid treatment is by successive volumes of acid each amounting to about 10% by volume of the oil treated and in which the strength of the acid,

' expressed as per cent H2804 is about 94% in the first treatment, 98% in the second treatment, and 103% in succeeding treatments.

7. The process of claim 3 in which the acid treatment is by successive volumes of acid each amounting to about 10% by volume of the oil treated and in which the strength of the acid, expressed as per cent H2804 is about 94% in the first treatment, 98% in the second treatment, and 103% in the succeeding treatments.

8. The process of claim 5 inwhlch the acid treatment is by successive volumes of acid each amounting to about 10% by volume of the oil treated and. in which the strength of the acid, expressed as per cent H2804 is about 94% in the first treatment, 98% in the second treatment, and

103% in succeeding treatments, and the desired sulphonic acid product is a mixture of those separated as a result of the fourth and fifth treattrolled strength, at least some of said treatments 7 ment stages.

9. A mineral oil sulphonic acid body highly soluble in both oil and water, prepared by treating alubricating oil distillate from Pennsylvania Crude oil with dichlorodiethyl ether to separate naphthenic constituents therefrom, freeing the extract of solvents to form asolvent' tar, subjecting said tar to distillation under an absolute pressure of the order of 1 inch of mercury absolute, collecting the distillate portions boiling between about C. and about 300 C. subjecting the distillate to five successive treatments with sulphuric acid, each with about one part of acid by volume to about ten parts of-oil, using acid of about 94% H2804 in the first treat, 98% acid in the second treat, and 103% acid thereafter, recovering the brown sulphonic acids remaining in the oil from the fourth and fifth treats separately from such sulphonic acids produced by the first three treats to produce a combined product of said sulphonic acids of the fourth and fifth treats, which combined product is both watersoluble and oil-soluble.

10. The process of producing brown sulphonic acid products of difierent solubilities which comprises treating an oil containing a substantial amount of cyclic compounds to sulphonating treatments of different intensities and recovering separately from each other brown sulphonic acid products produced by treatments of.different intensities.

,11. The process of producing a series of brown sulphonic acid products ranging from oil-insoluble to oil-solubleproducts which comprises subiecting a mineral oil to a series oi. sulphonation treatments with sulphuric acid, using acid of only sufiicient strength to produce water-soluble,

oil-insoluble brown sulphonic products at first, and then increasing the strength of the acid used for treats to produce oil-soluble brown sulphonic products, and recovering brown sulphonic acid products produced by treats of diflerent intensities separately from each other.

12. The process of producing brown sulphonic acid products which are highly water-soluble and relatively oil-insoluble comprising sulphonating a petroleum solvent tar containinga substantial amount of cyclic compounds of suitable molecular weight with sulphuric acid of sumcient strength to produce brown sulphonic acid product-s which are highly water-soluble and oil insoluble but of insufllcient strength to produce any substantial amount of brown sulphonic acid products which are relatively oil-soluble and recovering such water-soluble brown sulphonic acid product separately from any relatively oilsoluble brown sulphonic acid products 13. A process for the production or mineral oil sulphonic acid products which comprises sulphonating a petroleum solvent tar containing a substantial amount of cyclic compounds with successive treatments of sulphuric acid, using acid of only suflicient strength to produce watersoluble, oil-insoluble brown sulphonic products at first, and then increasing the strength of the acid used for treats to produce oil-soluble brown sulphonic products and recovering brown sulphonic acid products produced by treats of difierent intensities separately from each other.

14. The process of producing brown mineral oil sulphonic acid products which comprises sulphonating a suitable petroleum fraction containing a substantial amount of cyclic hydrocarbons with a sulphonating agent of suflicient strength to produce brown sulphonic acids, sulphonates of which are' highly water soluble and oil insoluble, but of insuflicient strength to produce any substantial amount of essentially difsubstantial amount of cyclic hydrocarbons, and

possessing a pour point below 0 F. before dewaxing, with sulphuric acid of sufiicient strength to form only brown petroleum sulphonic acids, sulphonates of which are highly water soluble and substantially insoluble in the oil, but of insuiiicient strength to produce any substantial amount of essentially different sulphonic acids, sulphonates of which are relatively oil soluble,

'forming water soluble, oil insoluble sulphonates of the sulphonic acids so produced, removing substantially all oil from su li sulphonates, and recovering a substantially oil-free water soluble, oil insoluble brown petroleum sulphonate product comprising such sulphonates.

16. A substantially oil-free mineral oil brown sulphonate product which is highly water soluble and oil insoluble produced by sulphonating a suitable mineral oil containing a substantial amount of cyclic hydrocarbons with a sulphonating agent of sufficient strength to produce'brown sulphonic acids, sulphonates of which are highly water soluble and oil insoluble, but of insufficient strength to produce any substantial amount of essentially diflerent brown sulphonic acids, sulphonates of which are relatively oil soluble, forming sulphonates of the sulphonic-acids so produced, removing substantially all oil from such sulphonates, and recovering a substantially oil-free water soluble, oil insoluble brown mineral oil sulphonate product comprising said latter sulphonates.

17. A substantially oil-free petroleum oil brown sulphonate product which is highly water soluble and oil insoluble produced by sulphonating a transformer oil stock containing a substantial amount of cyclic hydrocarbons, and having a pour point below 0 F. before dewaxing, with sulphuric acid of sufficient strength to produce brown sulphonic acids, sulphonates of which are highly water soluble and oil insoluble, but of insuflicient strength to produce any substantial amount of essentially different brown sulphonic acids, sulphonates of which are relatively oil soluble, forming sulphonates of the sulphonic-acids so produced, removing substantially all oil from such sulphonates, and recovering a substantially oil-free water soluble, oil insoluble brown mineral oil sulphonate product comprising said latter sulphonates.

ALEXANDER N.- SACHANEN. ARLIE A. OKELLY. PHAREZ G. WALDO. 

